Guide wire or working catheter with modified drive surface

ABSTRACT

An elongated medical device with a modified drive surface for use with the driving mechanism of a robotic system. The elongated medical device has a distal portion configured to navigate the lumen of a human body channel and a proximate portion with a surface different from that of the distal portion and adapted to better interact with the driving mechanism than the surface of the distal portion.

BACKGROUND

Guide wires are used to facilitate percutaneous procedures in which theguide wire and often guide and working catheters are threaded into ahuman patient using X-ray guidance. The guide wires are manuallythreaded by a physician or other medical personnel but this requiresthat the operator be adjacent to the patient and so be in the immediatevicinity of the X-ray radiation providing the image used for guidance.Systems have been developed, such as that disclosed in U.S. Pat. No.7,887,549 incorporated herein by reference, which allow the guide wiresand catheters to be threaded into the patient robotically and thus allowthe user or operator to be remote from the patient and the X-rayradiation. However, this involves the guide wire being mechanically, asopposed to manually, driven. Thus there is a concern about theinteraction between the surface of the guide wire and the drivingmechanism of the robotic system which may involve drive wheels and idlerwheels because the surface of the guide wire has been optimized forpassage through the interior of the human body. Therefore it may have asomewhat slippery surface which is not optimum for interaction with thedrive mechanism. This is also the case for robotically driven catheters.In addition the surface of the guide wire or catheter may be subject todamage or injury from its interaction with the drive mechanism,particularly when the drive mechanism involves wheels which apply apinch force.

SUMMARY

In one embodiment an elongated medical device with a modified drivesurface for use with the driving mechanism of a robotic system. Theelongated medical device has a distal portion configured to navigate thelumen of a human body channel and a proximate portion with a surfacedifferent from that of the distal portion and adapted to better interactwith the driving mechanism than the surface of the distal portion.

The present invention also involves a method of modifying a guide wireor working catheter, with a distal portion configured to navigate thelumen of a human body channel, to enhance its interaction with thedriving mechanism of a robotic system. A sleeve with a surface differentfrom that of the distal portion and adapted to better interact with thedriving mechanism than the surface of the distal portion is positionedover the proximate portion of the guide wire or working catheter suchthat it does not enclose the distal portion. Then the sleeve is causedto shrink in the radial direction such that it firmly engages the guidewire or working catheter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the environment in which a roboticsystem for driving a guide wire or working catheter in a percutaneousintervention procedure involving a human patient operates.

FIG. 2A is a top elevation of the drive mechanism of the robotic system.

FIG. 2B is a top cross sectional view of a guide wire with a modifiedproximate portion passing out of the drive mechanism and into and out ofa guide catheter.

FIG. 3A is a perspective view of a guide wire.

FIG. 3B is a perspective view of a guide wire with a proximate portionwith a modified surface.

FIG. 3C is a perspective view of a guide wire with a proximate portionwith a surface carrying a pattern.

FIG. 3C is a perspective view of a guide wire with a proximate portionwith a surface carrying a sleeve.

FIG. 4A is a perspective view of a sleeve being applied over theterminal end of a guide wire.

FIG. 4B is a perspective view of a sleeve being applied over theproximate portion of a guide wire.

FIG. 4D is a perspective view of a sleeve being applied by wrapping overthe proximate portion of a guide wire.

FIG. 4E is a perspective view of a helical coil sleeve being applied tothe proximate portion of a guide wire.

FIG. 5 is an axial cross section of the proximate portion of a guidewire between the wheels of a drive mechanism with a modified surface.

FIG. 6 is an axial cross section of the proximate portion of a guidewire between the wheels of a drive mechanism with a surrounding sleeve.

FIG. 7 is an axial cross section of the proximate portion of a guidewire between the wheels of a drive mechanism with a surrounding sleevewith a square outer surface.

FIG. 8 is an axial cross section of the proximate portion of a guidewire between specially adapted wheels of a drive mechanism with asurrounding sleeve with a square outer surface.

FIG. 9 is an axial cross section of the proximate portion of a guidewire between the wheels of a drive mechanism with a surrounding sleevewith an oval outer surface.

FIG. 10 is an axial cross section of the proximate portion of a guidewire between the wheels of a drive mechanism with a surrounding sleevewith wings projecting from its outer surface.

DETAILED DESCRIPTION

Referring to FIG. 1, one embodiment involves a system for performingpercutaneous intervention procedures on human patients in a cath lab 10in which an X-ray system 12 is used to monitor the procedure involvingthe patient 11 on the patient table 14. A robotic system 20 with a drivemechanism 22 is used to feed a guide wire 40 or working catheter and itsprogress is controlled and monitored from a remote console 24 that has acontrol panel 26 and a display 28 which is fed an image from the X-raysystem 12.

Referring to FIG. 2A, one embodiment involves a drive mechanism 22 thatuses a drive wheel 30 and an idler wheel 32 to impart axial motion 34 toa guide wire 40. The drive mechanism also imparts rotational motion 36to the guide wire 40. The drive mechanism 22 also includes a measurementwheel 31 and its idler 33. The measurement wheel 31 is linked to amechanism (not displayed), such a magnetic rotation measurementmechanism, which provides a measure of the axial motion of the guidewire 40. The accuracy of this measurement is dependent on theinteraction of the guide wire 40 with the measurement wheel 31 and canbe compromised by slippage between the two.

Referring to FIG. 2B, one embodiment involves a drive mechanism 22 thatfeeds a guide wire 40 into a guide catheter 50 which has typically beenmanually threaded into a blood vessel, such as the femoral artery, of apatient. Guide Catheter 50 has a distal end 52, and a proximate end 54.The guide wire 40 has a distal portion 42, which terminates in a tip 44which may have an arcuate shape or other profile proximate the tip 44,and a proximate portion 46, which interacts with the driving mechanism22. The distal portion 42 is designed to navigate the lumen of the bloodvessel and has the appropriate lubricity and flexibility to do so. Ithas the appropriate length to reach from the distal end 52 of the guidecatheter 50 to a location of interest within a patient. The proximateportion 46 has been provided with a sleeve 60 which facilitates itsinteraction with the drive mechanism 22 to impart both axial motion 34and rotational motion 36 to the guide wire 40. Note FIG. 2A and FIG. 2Bare schematic. The guide catheter 50 may be of the type that may besupported by a drive mechanism as disclosed in U.S. Pat. No. 7,887,549entitled Catheter System. The Figures are not meant to be to scale andare for illustrative purposes only. For example the length of the guidecatheter 50 and guide wire 40 may be longer than illustrated.

Referring to FIG. 3A, one embodiment involves the modification of aguide wire 40 that has a tip 44 at its distal end and has a proximateterminus 48. In one embodiment a guide wire as obtained from a supplierthat may have along its entire length from the tip 44 to the proximateterminus 48 a certain lubricity and flexibility appropriate to navigatethe lumen of a blood vessel.

Referring to FIG. 3B, one embodiment involves the modification of aguide wire 40 by applying a treatment, such as a chemical or laser etch,which causes the surface 47 of its proximate portion 46 to have a highercoefficient of friction than the untreated surface and thus to interactwith the drive mechanism 22 to facilitate axial movement 34 androtational movement 36.

Referring to FIG. 3C, one embodiment involves the modification of aguide wire 40 by applying a pattern, such as ridges angled at 45° to theaxis, to the surface 47 of its proximate portion 46. The patterninteracts with the drive mechanism 22 to facilitate axial movement 34and rotational movement 36.

Referring to FIG. 3D, one embodiment involves the modification of aguide wire 40 by covering its proximate portion 46 with a sleeve 60. Thepattern interacts with the drive mechanism 22 to facilitate axialmovement 34 and rotational movement 36.

Referring to FIG. 4A, one embodiment involves the modification of aguide wire 40 by sliding a sleeve 60 over its proximate terminus 48 orinserting this end 48 into the sleeve 60 so as to cover the proximateportion 46. This avoids the risk of damaging or altering the tip 44 andthe distal portion 42 and thereby affecting their ability to readilynavigate the lumen of a blood vessel.

Referring to FIG. 4B, one embodiment involves the modification of aguide wire 40 by using a sleeve 61 with an axial slit 62 to cover theproximate portion 46.

Referring to FIG. 4C, one embodiment involves the modification of aguide wire 40 by wrapping a rectangular strip 63 around the proximateportion 46 using a spiral wrapping pattern.

Referring to FIG. 4C, one embodiment involves the modification of aguide wire 40 by placing the proximate portion inside of a helical coil64 while it is in an axially compressed state 65 and then releasing thecompression. In the relaxed state 66 the coil 64 assumes a configurationwith a smaller inside radius that firmly grasps the proximate portion46.

Referring to FIG. 5, in the embodiment involving the surfacemodification 47, its interaction with the drive wheel 30 and its idlerwheel 32 can be seen. It is the modified surface 47 that contacts thesurfaces of these two wheels.

Referring to FIG. 6, in the embodiment involving the sleeve 60, itsinteraction with the drive wheel 30 and its idler wheel 32 can be seen.It is the sleeve 60 that contacts the surfaces of these two wheels. Thesleeve 60 may be conveniently affixed to the proximate portion 46 with apressure sensitive adhesive 72.

Referring to FIG. 7, a sleeve 67 with a square cross section has beenaffixed to the proximate portion 46. Not only does this provide moresurface area for interaction with the drive wheel 30 and its idler 32 inaxial motion, but it also enhances the interaction to impart rotationalmotion 36.

Referring to FIG. 8, a modified drive wheel 34 and its idler 35 havebeen provided to interact with the sleeve 67.

Referring to FIG. 9, a sleeve 68 with an oval cross section has beenaffixed to the proximate portion 46. Not only does this provide moresurface area for interaction with the drive wheel 30 and its idler 32 inaxial motion, but it also enhances the interaction to impart rotationalmotion 36.

Referring to FIG. 10, a sleeve 69 with wings 70 has been affixed to theproximate portion 46 and combined with a modified drive wheel 36 and itsidler 37. The wings 70 are quite helpful in imparting rotational motion36 to the guide wire 40.

The proximate portion 46 of a guide wire or working catheter may bemodified in a variety of ways to enhance its interaction with the drivemechanism 22 of the robotic system 20. In some embodiments its surfaceis modified to have a significantly higher coefficient of friction thanthe distal portion 42. In one embodiment its surface is imparted apattern of ridges and valleys. In another embodiment it is given anon-circular cross section, for instance by the application of a sleeve.

The various sleeves 60, 61, 63,67, 68 and 69 can be adhered to theproximate portion in a variety of ways. They can be constructed of amaterial, such as certain types of polymers that shrink in the radialdirection when exposed to appropriate conditions, such as heat orappropriate radiation, such as ultraviolet light. It is convenient ifthese conditions, particularly the heat, are such that they do not posea risk of damaging or modifying the distal portion 42. They can also beconstructed of materials that shrink in the radial direction whenstretched in the axial direction. Another approach is to interpose apressure sensitive coating between the surface of the proximate portion46 and the interior surface of the sleeve.

The sleeves conveniently have a circular interior cavity to accommodatethe typical guide wire or working catheter that typically has a circularcross section. However, in some embodiments the exterior surface of thesleeve is non-circular. One embodiment involves a sleeve with a crosssection with wings located opposite each other and extending radiallyoutward from an otherwise generally circular cross section.

There are a wide variety of surface modifications and methods ofapplying them to the surface of the proximate portion of the guide wireor working catheter so that it better interacts with the drive mechanismof a robotic system. The material out of which the guide wire or workingcatheter is constructed may allow some types of modification whileothers may be facilitated by the use of a sleeve. This surface may besubjected to a chemical, laser or plasma etch. It may be modified byproviding it with a grip, extra friction or nano coating. Because theentire surface of a guide wire or working catheter may be adapted tonavigating the lumen of a human body channel such as a blood vessel, ittypically already carries a coating which imparts high lubricity andcoating its proximate portion to better interact with the drivingmechanism of a robotic system may involve first removing this originalcoating. The surface of proximate portion may be given a design patternsuch as spirals, a circumferential tread or ridges angled at 45 degreesto this portions axis. This surface may be provided with a treadpattern. This surface may also be adapted to interact with particulardrive wheels forming part of the drive mechanism such as polyurethanewheels.

The surface modification of the proximate portion may also be used tobetter monitor and control the movement of the guide wire or workingcatheter. This surface may be provided optical or magnetic markers or agrid which can be read by appropriate sensors such as a torque sensor tomonitor the rotation and advancement of the guide wire or workingcatheter. The markers may be so configured such that any torque in theguide wire or working catheter may be readily determined and potentiallyused in instructing the drive mechanism. For instance, the surface maybe given a pattern which becomes skewed when the guide wire or workingcatheter is subjected to torque and appropriate sensors provided to readthis skewness. In one embodiment a sensor may detect twisting of theelongated device about its longitudinal axis by movement of the patternor optical markers or magnetic markers on the elongated medical device

In order to avoid effecting the original surface of the distal portionof the guide wire or working catheter, so that it retains its originallydesigned ability to readily navigate the lumen of a human body channel,the treatment of the proximate portion be effected from its proximateterminus. For instance, if a sleeve approach is used the sleeve may beslipped over this terminus and not advanced axially so far as to enclosethe distal portion.

The guide wire or working catheter with a modified proximate surfaceconveniently has a distal portion which has been imparted a lubricityand flexibility which optimizes its ability to navigate the lumen of ahuman blood vessel.

One embodiment involves the modified guide wire or working catheter witha guide catheter. In one embodiment the lengths of the proximal anddistal portions have been optimized such that when the guide catheter isin place and the guide wire or working catheter is advanced to the siteof action (area proximate a lesion) only the distal portion projectsbeyond the end of the guide catheter.

One embodiment involves combining the modified guide wire or workingcatheter with a guide catheter and a remotely controlled drive mechanismfor advancing a guide wire or working catheter into a lumen of a humanblood vessel. In one embodiment the guide wire or working catheter hasbeen modified to have a proximate portion which has a higher coefficientof friction than its distal portion and the lengths of the two portionsare such that when the guide catheter is in place and the guide wire orworking catheter is advanced to the site of action only the distalportion projects beyond the end of the guide catheter adjacent to thesite of action and the proximate portion extends back to the drivingmechanism.

Further modifications and alternative embodiments of various aspects ofthe invention will be apparent to those skilled in the art in view ofthis description. Accordingly, this description is to be construed asillustrative only and is for the purpose of teaching those skilled inthe art the general manner of carrying out the invention. Any of thefeatures, elements, or components of any of the exemplary embodimentsdiscussed above may be used alone or in combination with any of thefeatures, elements, or components of any of the other embodimentsdiscussed above. It is to be understood that the forms of the inventionshown and described herein are to be taken as presently preferredembodiments. Elements and materials may be substituted for thoseillustrated and described herein, parts and processes may be reversed,and certain features of the invention may be utilized independently, allas would be apparent to one skilled in the art having the benefit ofthis description of the invention. Changes may be made in the elementsdescribed herein without departing form the spirit and scope of theinvention as described in the following claims.

What is claimed is:
 1. An elongated medical device with a modified drivesurface for use with a drive mechanism of a robotic system comprising:an elongate body having a distal portion configured to navigate thelumen of a human body channel, and a proximate portion having aproximate surface different from that of the distal portion and adaptedto better interact with the driving mechanism than the surface of thedistal portion.
 2. The elongated medical device of claim 1 wherein theproximate portion surface has been modified to have a higher coefficientof friction than the distal portion.
 3. The elongated medical device ofclaim 2 wherein the surface of the proximate portion has been modifiedto have a pattern of ridges and valleys.
 4. The elongated medical deviceof claim 1 wherein the distal portion has a circular cross section andthe proximate portion has a non-circular cross section.
 5. The elongatedmedical device of claim 4 wherein the proximate portion has a crosssection with wings located opposite each other and extending radiallyoutward from an otherwise generally circular cross section.
 6. Theelongated medical device of claim 1 wherein the surface of the proximateportion has been provided by a sleeve which has been adhered to thesurface of the elongated medical device.
 7. The elongated medical deviceof claim 6 wherein the sleeve is constructed of a material which shrinksin the radial direction upon the application to it of heat, radiation oran axial force.
 8. The elongated medical device of claim 7 wherein thesleeve is constructed of a polymeric material which shrinks attemperature which is tolerated by the elongated medical device withoutimpairment.
 9. The elongated medical device of claim 6 wherein thesleeve is constructed of a helical coil which can be compressed in theaxial direction to have a larger inner diameter and has been releasedfrom such compression to firmly grasp the elongated medical device. 10.The elongated medical device of claim 1 wherein the surface of theproximate portion has been provided by mechanical or chemicalmodification of the surface of the elongated medical device.
 11. Theguide wire of claim 10 wherein the surface of the proximate portion hasbeen modified to have a greater coefficient of friction than the surfaceof the distal portion by etching of the guide wire with a laser.
 12. Theelongated medical device of claim l further including a guide cathetersuch that when the elongated medical device is driven to its terminalposition in the human body channel only the distal portion of theelongated medical device protrudes out of the end of the guide catheter.13. The elongated medical device of claim 1 wherein the distal portionhas been optimized for navigating the lumen of a human blood vessel andhas high lubricity and flexibility.
 14. The elongated medical device ofclaim 13 wherein the length has been optimized to extend from the drivemechanism into a human heart via a femoral artery and have only thedistal portion extend outside of a properly placed guide catheter.
 15. Arobotic percutaneous procedure system comprising: a remotely controlleddrive mechanism for advancing a guide wire or working catheter into achannel of the human body; a guide catheter which is placed in the humanbody channel; and a guide wire or working catheter having: a distalportion configured to navigate the lumen of a human body channel; aproximate portion with a surface different from that of the distalportion and adapted to better interact with the driving mechanism thanthe surface of the distal portion; and a length sufficient to extendfrom the drive mechanism to beyond the end of the guide catheter whichis distal from the drive mechanism, with the length of the proximalportion being such that it does not extend out of the guide catheterwhen the distal portion has reached its farthest extension into thehuman body channel.
 16. The system of claim 15 wherein the drivemechanism, guide catheter and the distal portion of the guide wire orworking catheter are adapted for use in a human blood vessel.
 17. Thesystem of claim 15 wherein the surface of the proximate portion has beenmodified to have a higher coefficient of friction than the surface ofthe distal portion.
 18. A method of modifying a guide wire or workingcatheter, with a distal portion configured to navigate the lumen of ahuman body channel, to enhance its interaction with the drivingmechanism of a robotic system comprising: positioning a sleeve with asurface different from that of the distal portion and adapted to betterinteract with the driving mechanism than the surface of the distalportion over the proximate portion of the guide wire or working cathetersuch that it does not enclose the distal portion; and causing the sleeveto shrink in the radial direction such that it firmly engages the guidewire or working catheter.
 19. The method of claim 18 wherein the sleeveis slipped over the proximate portion beginning at the proximateterminus of the proximate portion.
 20. The method of claim 18 whereinthe sleeve has an axial slit and the proximal portion is passed throughthis slit to the bore of the sleeve.
 21. The elongated medical device ofclaim 1, wherein the elongate body is one of a guide wire and acatheter.
 22. The elongated medical device of claim 1, wherein theproximate surface includes at least one of optical or magnetic markers.23. The elongated medical device of claim 1, wherein the proximatesurface includes a grid which can be read by a sensor to monitor therotation and advancement of the elongate body.
 24. The elongate medicaldevice of claim 23, wherein the grid on the proximate surface becomesskewed when the elongate medical device is subjected to torque.